The results of a study conducted 2008-2010 and released last Thursday concluded that free birth control led to lower rates of abortion and teen births among low-income women in St. Louis, Mo.

The project tracked more than 9,000 women, many of them poor and uninsured. When price wasn’t an issue, the women chose the more expensive and effective options of implanted birth control devices.

The results were impressive: 6.3 births per 1,000 teens as compared to a national average of 34 births per 1,000 in 2010. There were also 4.4-7.5 abortions per 1,000 women in the study, compared to 13.4-1...